1. Field of the Invention
The present invention generally relates to position control devices of moving bodies, stage devices using the position control devices, and position control methods of moving bodies. More particularly, the present invention relates to a position control device of a moving body, for which the position control device rotational operation of the moving body (stage) is prevented when both ends of the moving body are driven in a translational manner, a stage device using the position control device, and a position control method of a moving body.
2. Description of the Related Art
A device called an XY stage device has a structure where an X stage moving in an X direction is provided at a Y stage moving in a Y direction. The XY stage device has a position control device of a moving body. The position control device controls moving positions of the stages (moving bodies).
In addition, there is a device called a gantry moving type stage device among these kinds of the devices. As discussed in Japanese Laid-Open Patent Application Publication No. 2001-238485 (Japanese Patent No. 3481540), in the gantry moving type stage device, a gate shape first moving body, namely a Y stage, moves above a substrate held on a table at a constant speed.
A second moving body, namely an X stage, is provided at the first moving body. The second moving body moves in an X direction perpendicular to the Y direction. Various kinds of jigs are provided on the second moving body. In the XY stage device, while the second moving body is moved to an optional position of a X direction stroke, the first moving body is moved in the Y direction.
Thus, in a case where the first moving body is moved in the Y direction while the second moving body is moved in the X direction, if a command value is output so that the same thrust forces (driving forces) are generated by first and second linear motors configured to drive the first moving body, the position of the center of gravity of a moving body unit including the first and second moving bodies is changed accompanying movement of the second moving body. Therefore, a rotational force whose center is a Z axis crossing the position of the center of gravity acts on the moving body unit.
Because of this, in a state where the second moving body is not positioned in the center of a moving area in the Y direction, for moving the first moving body in the Y direction, two thrust forces from a pair of the linear motors applied to the first moving body are made different so that moments of two forces around the center of gravity of the first moving body by both thrust forces cancel each other.
As a result of this, the moments of two forces around the center of gravity generated by the thrust force for driving the first moving body in a translational manner cancel each other, so that the thrust force is prevented from applying a rotational force to the first moving body.
However, in the above-discussed related art XY stage device, two thrust forces applied from a pair of the linear motors to the first moving body are controlled so that the moments of forces around the center of gravity generated by the two thrust forces cancel each other. Therefore, for example, even if a force in a rotational direction acts on the first moving body due to disturbance so that the first stage is rotated at a certain angle and the first stage is inclined in the yawing direction, the thrust forces of a pair of the linear motors are determined on the assumption that the first stage is driven so as to not be inclined against the X axial direction.
Because of this, in the related art XY stage device, if the first stage is rotated at a designated angle with respect to the Z axis, the first stage is driven in the Y direction in a state where inclination with the X axis is not corrected.
Therefore, when the disturbance is input, in the above-discussed feedback control, it may be difficult to drive the moving body in a translational manner with high precision and without rotating the moving body in the yawing direction.